Lumens per watt to lumens per BTU per hour
Type a value in lm/W to get it in lm/(BTU/h) instantly.
29.31lm/(BTU/h)
That's 1.67× as efficient as a fluorescent tube, while a modern LED is 1.2× better. An 800 lumen bulb at that efficiency would draw about 8 watts.
What it means
How efficient is that?
The 683 lm/W ceiling is for pure 555 nm green light. Any usable white light must spread across the spectrum, so about 250–350 lm/W is the practical limit.
The math
How to convert lm/W to lm/(BTU/h)
To convert lumens per watt to lumens per BTU per hour, multiply by 0.293071.
Example: 100 lm/W × 0.293071 = 29.3071 lm/(BTU/h).
In the other direction, 1 lm/(BTU/h) = 3.41214 lm/W.
Every unit
Your efficacy in every unit
Tables
lm/W to lm/(BTU/h) conversion table
| lm/W | lm/(BTU/h) |
|---|---|
| 5 lm/W | 1.46536 lm/(BTU/h) |
| 10 lm/W | 2.93071 lm/(BTU/h) |
| 15 lm/W | 4.39607 lm/(BTU/h) |
| 25 lm/W | 7.32678 lm/(BTU/h) |
| 50 lm/W | 14.6536 lm/(BTU/h) |
| 75 lm/W | 21.9803 lm/(BTU/h) |
| 100 lm/W | 29.3071 lm/(BTU/h) |
| 150 lm/W | 43.9607 lm/(BTU/h) |
| 200 lm/W | 58.6142 lm/(BTU/h) |
| 300 lm/W | 87.9213 lm/(BTU/h) |
| 683 lm/W | 200.168 lm/(BTU/h) |
lm/(BTU/h) to lm/W conversion table
| lm/(BTU/h) | lm/W |
|---|---|
| 5 lm/(BTU/h) | 17.0607 lm/W |
| 10 lm/(BTU/h) | 34.1214 lm/W |
| 15 lm/(BTU/h) | 51.1821 lm/W |
| 25 lm/(BTU/h) | 85.3036 lm/W |
| 50 lm/(BTU/h) | 170.607 lm/W |
| 75 lm/(BTU/h) | 255.911 lm/W |
| 100 lm/(BTU/h) | 341.214 lm/W |
| 150 lm/(BTU/h) | 511.821 lm/W |
| 200 lm/(BTU/h) | 682.428 lm/W |
| 300 lm/(BTU/h) | 1,023.64 lm/W |
| 683 lm/(BTU/h) | 2,330.49 lm/W |
Quick answers
Quick answers
- How many lm/(BTU/h) is 1 lm/W?
- 1 lm/W is 0.293071 lm/(BTU/h).
- How many lm/(BTU/h) is 10 lm/W?
- 10 lm/W is 2.93071 lm/(BTU/h).
- How many lm/(BTU/h) is 100 lm/W?
- 100 lm/W is 29.3071 lm/(BTU/h).
The units
About these units
Lumens per watt (lm/W)
The standard measure of lighting efficiency.
Lumens per BTU per hour (lm/(BTU/h))
A US form, for comparing lighting with heating loads.
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